1/*
2 * Copyright (C) 2014 Samsung Electronics Co., Ltd.
3 * Sylwester Nawrocki <s.nawrocki@samsung.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/clk.h>
11#include <linux/clk-provider.h>
12#include <linux/clk/clk-conf.h>
13#include <linux/device.h>
14#include <linux/of.h>
15#include <linux/printk.h>
16
17static int __set_clk_parents(struct device_node *node, bool clk_supplier)
18{
19	struct of_phandle_args clkspec;
20	int index, rc, num_parents;
21	struct clk *clk, *pclk;
22
23	num_parents = of_count_phandle_with_args(node, "assigned-clock-parents",
24						 "#clock-cells");
25	if (num_parents == -EINVAL)
26		pr_err("clk: invalid value of clock-parents property at %s\n",
27		       node->full_name);
28
29	for (index = 0; index < num_parents; index++) {
30		rc = of_parse_phandle_with_args(node, "assigned-clock-parents",
31					"#clock-cells",	index, &clkspec);
32		if (rc < 0) {
33			/* skip empty (null) phandles */
34			if (rc == -ENOENT)
35				continue;
36			else
37				return rc;
38		}
39		if (clkspec.np == node && !clk_supplier)
40			return 0;
41		pclk = of_clk_get_from_provider(&clkspec);
42		if (IS_ERR(pclk)) {
43			pr_warn("clk: couldn't get parent clock %d for %s\n",
44				index, node->full_name);
45			return PTR_ERR(pclk);
46		}
47
48		rc = of_parse_phandle_with_args(node, "assigned-clocks",
49					"#clock-cells", index, &clkspec);
50		if (rc < 0)
51			goto err;
52		if (clkspec.np == node && !clk_supplier) {
53			rc = 0;
54			goto err;
55		}
56		clk = of_clk_get_from_provider(&clkspec);
57		if (IS_ERR(clk)) {
58			pr_warn("clk: couldn't get parent clock %d for %s\n",
59				index, node->full_name);
60			rc = PTR_ERR(clk);
61			goto err;
62		}
63
64		rc = clk_set_parent(clk, pclk);
65		if (rc < 0)
66			pr_err("clk: failed to reparent %s to %s: %d\n",
67			       __clk_get_name(clk), __clk_get_name(pclk), rc);
68		clk_put(clk);
69		clk_put(pclk);
70	}
71	return 0;
72err:
73	clk_put(pclk);
74	return rc;
75}
76
77static int __set_clk_rates(struct device_node *node, bool clk_supplier)
78{
79	struct of_phandle_args clkspec;
80	struct property	*prop;
81	const __be32 *cur;
82	int rc, index = 0;
83	struct clk *clk;
84	u32 rate;
85
86	of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) {
87		if (rate) {
88			rc = of_parse_phandle_with_args(node, "assigned-clocks",
89					"#clock-cells",	index, &clkspec);
90			if (rc < 0) {
91				/* skip empty (null) phandles */
92				if (rc == -ENOENT)
93					continue;
94				else
95					return rc;
96			}
97			if (clkspec.np == node && !clk_supplier)
98				return 0;
99
100			clk = of_clk_get_from_provider(&clkspec);
101			if (IS_ERR(clk)) {
102				pr_warn("clk: couldn't get clock %d for %s\n",
103					index, node->full_name);
104				return PTR_ERR(clk);
105			}
106
107			rc = clk_set_rate(clk, rate);
108			if (rc < 0)
109				pr_err("clk: couldn't set %s clock rate: %d\n",
110				       __clk_get_name(clk), rc);
111			clk_put(clk);
112		}
113		index++;
114	}
115	return 0;
116}
117
118/**
119 * of_clk_set_defaults() - parse and set assigned clocks configuration
120 * @node: device node to apply clock settings for
121 * @clk_supplier: true if clocks supplied by @node should also be considered
122 *
123 * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
124 * and sets any specified clock parents and rates. The @clk_supplier argument
125 * should be set to true if @node may be also a clock supplier of any clock
126 * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
127 * If @clk_supplier is false the function exits returnning 0 as soon as it
128 * determines the @node is also a supplier of any of the clocks.
129 */
130int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
131{
132	int rc;
133
134	if (!node)
135		return 0;
136
137	rc = __set_clk_parents(node, clk_supplier);
138	if (rc < 0)
139		return rc;
140
141	return __set_clk_rates(node, clk_supplier);
142}
143EXPORT_SYMBOL_GPL(of_clk_set_defaults);
144